Cancer treatment requires a medical certificate that proves presence of a cancer cell, which medical certificate is made by a pathological diagnosis. The pathological diagnosis determines, on the basis of morphological evidence obtained through microscopic observation, whether or not a cancer cell is present.
However, the absolute number of pathologists who can carry out such a pathological diagnosis is insufficient. There are facilities, such as a hospital in a remote area, where no full-time pathologist works. In such a facility, there may be a case where the pathological diagnosis cannot be carried out immediately when it is required. This causes a delay in starting on cancer treatment. Particularly, if a possible cancer tissue is found during an operation in a hospital where no pathologist works, it is then impossible to (i) appropriately decide a therapeutic strategy and (ii) determine which part is to be excised. The insufficiency in the number of such pathologists has been therefore pointed out as a significant problem.
Due to such a shortage of the pathologists, the number of pathological diagnoses performed per pathologist is increased, and this results in an increase in risk of occurrence of a diagnostic error (human error). In fact, there has been reported in the U.S. such a case that (i) few pathologists had to carry out a lot of diagnoses during a group medical examination for uterus cancer and (ii) this causes presence of cancer to be overlooked a lot in the group medical examination. There was even a case where such a human error led to a lawsuit. Further, the pathological diagnosis is carried out by a subjective decision on the basis of a morphological evidence of a tissue or a cell, which evidence is obtained through the microscopic observation. In some cases, it is difficult to morphologically determine whether or not cancer is present. In this regard, a more objective way has been demanded for the pathological diagnosis.
Under the circumstances, application of an image processing technique to screening for uterus cancer has been attempted in Japan. Cancer screening employing the image processing technique allows determination of presence of cancer without a pathologist being in an actual site where the cancer screening is carried out. According to the screening for uterus cancer, which employs the image processing technique, it is determined whether or not a cell is a cancer cell by finding, in an image of the cell, (i) a size of a nucleus, (ii) a ratio of the nucleus to a cytoplasm (N/C ratio), and/or (iii) a chromatin pattern.
Meanwhile, “AutoPap (Focal Point)” has been known as an image diagnosis system for recognizing a malignant cell by carrying out pattern recognition of a cancer cell. Performance of the AutoPap (Focal Point) is reported in Non-Patent Literatures 1 through 5. Further, a mechanism of the Auto Pap (Focal Point) is reported in Non-Patent Literature 6.
Furthermore, each of Non-Patent Literatures 7 and discloses a technique for (i) morphologically presenting a cancer tissue in a three-dimensional manner by use of the Betti numbers and (ii) analyzing the cancer tissue.